Taxonomic note of Parnassia (Celastraceae): the identity of P. yui

$¢PhytoKeys

PhytoKeys 251: 251-256 (2025)
DOI: 10.3897/phytokeys.251.140807

Research Article

Taxonomic note of Parnassia (Celastraceae): the identity of P. yui

Shi-Qi Wang', Xue-Mei Zhang', Yu-Min Shu"

1 College of Life Science, China West Normal University, Nanchong 637002, China
2 Key Laboratory of Southwest China Wildlife Resource Conservation (Ministry of Education), Nanchong 637002, China
Corresponding author: Yu-Min Shu (shuyumin@cwnu.edu.cn)

OPEN Qaceess

Academic editor: Bo Li
Received: 5 November 2024
Accepted: 30 December 2024
Published: 29 January 2025

Citation: Wang S-Q, Zhang X-M,
Shu Y-M (2025) Taxonomic note
of Parnassia (Celastraceae): the
identity of P yu’. PhytoKeys 251:
201-256. https://doi.org/10.3897/
phytokeys.251.140807

Copyright: © Shi-Qi Wang et al.
This is an open access article distributed under
terms of the Creative Commons Attribution

License (Attribution 4.0 International - CC BY 4.0).

Abstract

Parnassia farreri is characterised by the petals with long-ciliate petal claw and the broad
spatulate staminodes with shallow crenations distally. A sympatric and poorly-known
taxon, P. yui, is recorded only from the type collection that morphologically similar to
P farreri. Based on field investigations, examination of herbarium specimens (including
the types) and analysis of protologues and distributions, P yui is hereby reduced to a
synonym of P farreri. Field and anatomy photographs and an updated morphological de-
scription of P farreri are provided. Parnassia farreri is preliminarily designated as Least
Concern according to the IUCN Red List guidelines.

Key words: Morphology, Parnassia, staminode, synonymy, taxonomic uncertainty

Introduction

Parnassia L. (Linnaeus 1753) is a fairly homogeneous and distinguishable ge-
nus of Celastraceae (APG IV 2016; Ball 2016), consisting of small and glabrous
perennial herbs, with a solitary, bisexual and pentamerous flower that has five
staminodes borne on an unbranched scape (Ku 1987; Ku and Hultgard 2001).
Species of Parnassia predominantly occur in alpine and arctic regions of the
Northern Hemisphere, which most diverse in Pan-Himalaya and southwest Chi-
na (Phillips 1982; Wu et al. 2003; Simmons 2004; Wu 2005). The most recent
checklist of Parnassia worldwide was accomplished by Shu et al. (2017) and
contains 61 species, two subspecies, 11 varieties and one form. Since then,
more than ten names have been reduced to synonyms (Shu et Zhang 2017;
Wang et al. 2018; Yu et al. 2018; Ma et al. 2020; Dai et al. 2021) and two new
species were described (Zhang et al. 2019).

Parnassia farreri W. E. Evans (1921: 174) was formally described, based on
the specimens of R. Farrer 1211 (Fig. 1A) which was collected from Myanmar.
The petal base of this species is abruptly contracted into a claw with long ciliat-
ed margin, that is distinctive in this genus. Parnassia yui Jien (1963: 256), anoth-
er species with similar morphological features and neighbouring distribution to
P farreri, was described, based on a single collection (T. T. Yu 20238, Fig. 1B, 24
individuals mounted on four sheets) from Yunnan Province, China. According to
the original description, the morphological differences betweenP yuiandP farreri
include the larger leaves blades (12-24 x 12-24 mm vs. 2-14 x 2-14 mm),

291

Shi-Qi Wang et al.: Taxonomic note of Parnassia (Celastraceae): the identity of P yui

Hotolyne Specimen

Parnassia Farreri, WE. Evans. Sp. nov.

liberum apice breviter contractum, stylo nullo, stigmatibus tri-
bus rectis sessilibus,

mon and now prominent as there is not much in “flower,
Grows in patches, 30.8.19."" F. Kingdon Ward: No. aso9.

integris munitas hace caulibus flori-_
infra longe fimbriatis, stigmatibus

ie vel ad dnas partes atti
latas hand productis. Ov:

tum basi

Valley. Alt. 11,000 ft. Flowers
middle alpine zone,

ii

ii A tes

Figure 1. Holotypes of Parnassia farreri (A E00079815) and P yui (B PEO1842927).

the acute or acuminate (vs. rounded) apexes of narrower petals and the three
lobed (vs. entire or obscurely sinuate) apex of staminodes.

Through observation of herbarium specimens, we found these two species
are extremely similar in morphology and there is obvious overlap in the shape
of leaf blades and staminodes. Therefore, the aim of this study was to clarify
the classification relationship between P farreri and P. yui by re-evaluating their
morphological characteristics.

Materials and methods

The type specimens of P farreri and P yui, along with other related specimens
deposited at KUN, PE and SITC, were meticulously inspected. Additionally, digi-
tised material sourced from Herbaria CAS and E (acronyms according to Thiers
(2024)) were carefully examined. Field investigations were carried out during
September to October of 2024 in Gongshan County, Yunnan Province, China.
Eleven individuals with well-preserved leaves and flowers from the type speci-
mens of P yui and fifty individuals of P farreri from the wild were used to conduct
the morphological measurement and comparison. Eight morphological charac-
ters, i.e. leaf length, leaf width, ratio of leaf length/width, petal length, petal width,
ratio of petal length/width, number of staminode lobes and depth of staminode
lobes were measured in this study. Principal Component Analysis (PCA) was per-
formed to investigate the morphological variations between P farreri and P. yui.

PhytoKeys 251: 251-256 (2025), DOI: 10.3897/phytokeys.251.140807 252

Shi-Qi Wang et al.: Taxonomic note of Parnassia (Celastraceae): the identity of P yui

Results

During the specific field survey of P farreri populations in southwest China, we
documented continuous variations of leaf blades, the shapes of petals and
staminodes (Fig. 2A-E), even sometimes within individuals. No specimens
of P yui were traced, except the type materials. Amongst the individuals from
the type materials of P yui, only a few have oblanceolate petals and shallowly
3-lobed staminodes, that match the original description. Additionally, most in-
dividuals have triangular-ovate to ovate-spartulate petals, as well as irregular
dentate staminodes apexes (Fig. 2F—-G). Principal Component Analysis (PCA)
could not distinguish these two taxa, the 95% confidence ellipse of P. farreri
being almost included in that of P yui (Fig. 3). Furthermore, the distribution of
P. yui is limited in Gongshan County, Yunnan, China and, in this region, more
than ten specimens of P farreri have been collected. The latter taxon is also
distributed in Myanmar and India (Shu et al. 2017; Pankaj et al. 2018). Since the
lack of clear morphologic distinctions and the overlapping distribution range,
we hereby propose to reduce P yui to a synonym of P. farreri.

Taxonomic treatments

Parnassia farreri W.E. Evans (1921: 174)

Type. MYANMAR * Chimely Valley, in the middle alpine zone, 3300 m, 15 August
1919, R. Farrer 1211 (holotype: E00079815 photo!).

Parnassia yui Jien (1963: 256)

Type. CHINA * Yunnan, Salwin-Kiukiang Divide, northeast of Sinpu, under bamboo
thickets, 3000 m, 14 September 1938, T. T. Yu 20238 (holotype: PEO1842927!:
isotypes: PEO1842926!, KUN1205235!, KUN1205238!)

Description. Perennial herbs, glabrous. Rhizome sympodial. Stems 1 to 4,
slender, 3-16 cm, with a tiny cauline leaf near middle. Basal leaves 1 to 7, peti-
ole 1-4.5 cm; blade reniform, broad cordate or orbicular, 0.2—2.4 x 0.2-2.8 cm,
base cordate, apex rounded or apiculate. Flower 0.8-1.5 cm in diam.; hypanthi-
um turbinate. Sepals oblong, ovate or lanceolate, 2-3 x 1-2 mm, margin entire,
apex acute. Petals white, densely purple-brown punctuate when dried, oblance-
olate, triangular-ovate, to ovate-spartulate, 3-6 x 1.5-3.5 mm, base contract-
ed into a claw ca. 2 mm, margin long fimbriate proximally, entire distally, apex
acute to rounded-obtuse. Anthers ellipsoid, filaments 2-—2.5 mm. Staminodes
flat, broadly spatulate, 2 x 1-2 mm, apex shallowly 3-lobed, dentate, undulate or
rounded. Ovary superior, broadly ovoid; style ca. 1 mm; stigma 3-lobed. Capsule
depressed ovoid. Seeds brown, glossy, oblong.

Phenology. Flowering from July to September, fruiting from August to October.

Distribution. China, Myanmar and India.

Habitats. Under shrubs, grassy rocks, ledges and slopes at an elevation of
3000-3900 m.

Additional specimens examined. CHINA. Yunnan, Gongshan County:
° 3252 malt., 21 August 2024, Y.M. Shu et. al. $1166 (SITC); * 3336 m, 21 August

PhytoKeys 251: 251-256 (2025), DOI: 10.3897/phytokeys.251.140807 959

Shi-Qi Wang et al.: Taxonomic note of Parnassia (Celastraceae): the identity of P yui

Figure 2. Morphology of Parnassia farreri A habitat B flower C leaves D variation of petals E variation of staminodes and
P yui F petals G staminodes, photographed from T. T. Yu 20238, the type specimen.

2024, Y.M. Shu et. al. $1168 (SITC); * 3399 m alt., 21 August 2024, Y.M. Shu et. al.
$1170 (SITC); 30 July 2013, X.H. Jin et al. st7518 (PEO1979311!); - 3600 m alt.,
29 July 2013, X.H. Jin et al. st1357 (PE!); * 3300 m alt., 22 July 2013, X.H. Jin et
al. STO741 (PE!); 2 September 2011, S.X. Yu et al. 6527 (PE!); 24 August 2009,
WWZ 126 (KUN!); * 3250 m alt., 19 September 2003, J.H. Chen 30571 (KUN!);
- 3600 m, 19 September 2003, J.H. Chen 3053 (KUN!); 19 August 2003, J.M. Lu
et al. 2319 (KUN!); * 3080 m alt., 2 October 2002, Gaoligong Shan Biodiversity
Survey16895 (CAS0321223!); * 3400 m alt., 9 September 1940, K.M. Feng 7619
(PE00866103!, KUN0437239!, KUN0437240!); * 3300 m alt., 20 August 1937,
T.T. Yu 22447 (PE01982464!, PEO1982465!, PEO0866102!); * 3100 m alt., 1 Oc-
tober 1935, Q.W. Wang 67226 (PE00866104!): Fugong County: - 3700 m alt., 16
August 2005, H. Li et al. 28515 (CAS0321224!); - 20 August 2003, 2800 m alt.,
J.M. Lu et L.M. Gao 2327 (KUN!); Lushui County: » 3050 m alt., 08 August 2011,
X.H. Jin et al. 11171 (PEO2025103!).

MYANMAR. « 3600 m, 30 August 1919, F Kingdon Ward. 3599 (E00275515 photo!).

Conservation status. The conservation status of both P farreri and P. yui
have not been evaluated before. At present, P. farreri has been reported from
China, Myanmar and India. Based on our field investigations, numerous indi-
viduals could be easily discovered under shrubs, in grassy slopes or on ledges,
indicating the population survives and regenerates well. Thus, we propose to
list P farreri as Least Concern (LC) according to the IUCN Red List Categories
and Criteria (IUCN Standards and Petitions Committee 2022).

PhytoKeys 251: 251-256 (2025), DOI: 10.3897/phytokeys.251.140807 954

Shi-Qi Wang et al.: Taxonomic note of Parnassia (Celastraceae): the identity of P yui

5.0- I

2.5 -

a [e| P.farreri
[4] P.yui

—25 -

10 20 30
PC1(91.6%)

Figure 3. The Principal Component Analysis (PCA) plot for the morphological variations
between Parnassia farreri and P. yui. The confidence ellipse level is 95%.

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Funding

This work was financially supported by the Scientific Research Foundation of China
West Normal University (Grant no. 416876).

Author contributions

All authors have contributed equally.

Data availability

All of the data that support the findings of this study are available in the main text.

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PhytoKeys 251: 251-256 (2025), DOI: 10.3897/phytokeys.251.140807 256